Screen printing tissue models

Abstract

A process of simply, cheaply, and reproducibly creating complex tissue models using screen printing and the tissue model prepared using the screen printing process. These models are amenable to high throughput screening. They will allow the study of components of disease progression and can be used for screening therapies.

What is claimed is: 
     
       1. A process of making a multilamellar tissue model, said process comprising:
 (a) positioning a first screen having an exposed first pattern over a substrate; 
 (b) placing a first solution to be printed onto the first screen, wherein the first solution comprises a hydrogel and optionally an additional constituent; 
 (c) pushing a blade across the first screen to spread the first solution into the exposed first pattern; 
 (d) removing the first screen to reveal a first layer comprising the hydrogel and optionally the additional constituent; 
 (e) positioning a second screen having an exposed second pattern over the first layer; 
 (f) placing a second solution to be printed onto the second screen, wherein the second solution comprises one or more of a protein, a cell, additional hydrogel, additional hydrogel comprising an additional constituent, collagen, gelatin, and any combination thereof; 
 (g) pushing a blade across the second screen to spread the second solution into the exposed second pattern; and 
 (h) removing the second screen to reveal a second layer positioned on the first layer comprising the hydrogel, 
 wherein the process does not require exposure of the layers to UV light, bioinks, or shearing processes. 
 
     
     
       2. The process of  claim 1 , wherein the multilamellar tissue model comprises (i) the substrate, (ii) the first layer comprising at least one layer comprising a hydrogel, and (iii) the second layer comprising one or more of a protein, a cell, additional hydrogel, additional hydrogel comprising an additional constituent, collagen, gelatin, and any combination thereof. 
     
     
       3. The process of  claim 1 , wherein the multilamellar tissue model further comprises at least one electrode patterned therein. 
     
     
       4. The process of  claim 1 , wherein the model comprises at least one cell-permissive portion and a non cell-permissive portion. 
     
     
       5. The process of  claim 1 , wherein the hydrogel comprises poly(ethylene glycol) (PEG), gelatin, or both. 
     
     
       6. The process of  claim 5 , wherein the hydrogel further comprises an additional constituent selected from the group consisting of polylysine (PLL), hyaluronic acid (HA), poly-γ-(glutamic acid) (γ-PGA), poly(aspartic acid) (PAA), poly(arginine), and any combination thereof. 
     
     
       7. The process of  claim 6 , wherein the additional constituent further comprises a protein that was absorbed to, or reacted with, the additional constituent. 
     
     
       8. The process of  claim 1 , wherein the substrate comprises a material selected from the group consisting of glass, stainless steel, metal, ceramic, plastic, gas-permeable membranes, polysiloxanes, fabric, degradable polymer films, degradable polymer membranes, electrospun materials, and any combination thereof. 
     
     
       9. The process of  claim 1 , wherein the solutions are aqueous and further comprise at least one component selected from the group consisting of physiologically appropriate buffers, salts, sugars, proteins and drugs. 
     
     
       10. The process of  claim 1 , wherein the second layer comprises cells and wherein greater than 60% of the cells survive the screening process without differentiation and without the presence of a matrix which augments survival. 
     
     
       11. The process of  claim 1 , wherein at least one pattern has a resolution in a range from about 20 μm to about 500 μm. 
     
     
       12. The process of  claim 1 , further comprising the printing of a third layer, said process comprising
 (i) positioning a third screen having an exposed third pattern over the second layer; 
 (j) placing a third solution to be printed onto the third screen, wherein the third solution comprises one or more of proteins, cells, additional hydrogel, additional hydrogel comprising an additional constituent, collagen, gelatin, and any combination thereof; 
 (k) pushing a blade across the third screen to spread the third solution into the exposed third pattern; and 
 (l) removing the third screen to reveal a third layer positioned on the second layer. 
 
     
     
       13. The process of  claim 12 , further comprising printing a fourth layer, optionally a fifth layer, optionally a sixth layer, optionally a seventh layer, optionally an eighth layer, optionally a ninth layer, and optionally a tenth layer using a process analogous to the printing of any of the first, second, or third layers. 
     
     
       14. The process of  claim 1 , wherein hydrogel layers are able to set up, crosslink, or phase separate without exposure to light. 
     
     
       15. The process of  claim 1 , wherein hydrogel layers gel using vinylsulfone-thiol chemistry. 
     
     
       16. The process of  claim 1 , wherein the additional constituent is selected from the group consisting of polylysine (PLL), hyaluronic add (HA), poly-y-(glutamic add) (y-PGA), poly(aspartic add) (PAA), poly(arginine), and any combination thereof.